SQLite绑定文本值与检索到的文本值

Question

我有以下Database类创建数据库并包含将Movie添加到数据库的方法。我在那里有几个打印语句用于调试。

import Foundation
import SQLite3

class SQLiteDatabase
{

    private var db : OpaquePointer?

    init (databaseName dbName: String){
        //Get a file handle, or create handle.
        let fileURL = try! FileManager.default.url(for: .documentDirectory, in: .userDomainMask, appropriateFor: nil, create: false).appendingPathComponent("\(dbName).sqlite")

        //try and open filepath as databse
        if sqlite3_open(fileURL.path, &db) == SQLITE_OK
        {
            print("Sucessfully opened connection to database as \(fileURL.path)")
        }
        else
        {
            print("Unable to open databse at \(fileURL.path)")
            printCurrentSQLErrorMessage(db)
        }
    }

    deinit {
        sqlite3_close(db)
    }

    func insert(movie:Movie){
        let insertStatementQuery =
        "INSERT INTO Movie (ID,Name,Year,Director) VALUES (?,?,?,?);"

        var insertStatement: OpaquePointer?
        if sqlite3_prepare_v2(db, insertStatementQuery, -1, &insertStatement, nil) == SQLITE_OK
        {
            sqlite3_bind_int(insertStatement, 1, movie.ID)
            sqlite3_bind_text(insertStatement, 2, movie.name, -1, nil)
            sqlite3_bind_int(insertStatement, 3, movie.year)
            sqlite3_bind_text(insertStatement, 4, movie.director, -1, nil)
            print("Name value in is: \(movie.name), Director Value in is: \(movie.director)")

            if sqlite3_step(insertStatement) == SQLITE_DONE
            {
                print("Sucesfully inserted row")
            }
            else
            {
                print("Could not insert row")
                printCurrentSQLErrorMessage(db)
            }
        }
        else
        {
            print("INSERT statement could not be prepared.")
            printCurrentSQLErrorMessage(db)
        }

        sqlite3_finalize(insertStatement)
    }

    func selectAllMovie() -> [Movie]{
        var result = [Movie]()
        let selectStatementQuery = "SELECT ID,Name,Year,Director FROM Movie"

        //prepare statement
        var selectStatement : OpaquePointer? = nil
        if sqlite3_prepare_v2(db, selectStatementQuery, -1 , &selectStatement, nil) == SQLITE_OK
        {
            //iterate over result
            while sqlite3_step(selectStatement) == SQLITE_ROW
            {
                //create movie object from result
                let movie = Movie(
                    ID: sqlite3_column_int(selectStatement, 0),
                    name: String(cString:sqlite3_column_text(selectStatement, 1)),
                    year: sqlite3_column_int(selectStatement, 2),
                    director: String(cString:sqlite3_column_text(selectStatement, 3))
                )


                print(String(cString: sqlite3_column_text(selectStatement, 1)))
                print(String(cString: sqlite3_column_text(selectStatement, 3)))

                print("Name value out is: \(movie.name), Director Value out is: \(movie.director)")

                //add result to array
                result += [movie]
            }
        }
        else
        {
            print("SELECT statement could not be prepared.")
            printCurrentSQLErrorMessage(db)
        }

        //cleanup
        sqlite3_finalize(selectStatement)

        return result
    }

    func printCurrentSQLErrorMessage(_ db : OpaquePointer?){
        let errorMessage = String.init(cString : sqlite3_errmsg(db))
        print ("Error:\(errorMessage)")
    }

    func createMovieTable(){
        let createTableQuery = """
            CREATE TABLE Movie (
                ID INTEGER PRIMARY KEY NOT NULL,
                Name CHAR(255),
                Year INTEGER,
                Director CHAR(255)
            );
        """

        //prepare statement
        var createTableStatement : OpaquePointer?  = nil
        if sqlite3_prepare_v2(db, createTableQuery, -1, &createTableStatement, nil) == SQLITE_OK
        {
            //execute the statement
            if sqlite3_step(createTableStatement) == SQLITE_DONE
            {
                print("Movie Table Done")
            }
            else
            {
                print("Movie table could not be created")
                printCurrentSQLErrorMessage(db)
            }
        }
        else
        {
            print("CREATE TABLE statement could not be prepared")
            printCurrentSQLErrorMessage(db)
        }

        //cleanup
        sqlite3_finalize(createTableStatement)
    }
}

我有以下代码添加两个条目

database.createMovieTable()
    database.insert(movie: Movie(ID: 0, name: "ExtraLong", year: 2018, director: "Bob Ross"))
    database.insert(movie: Movie(ID: 1, name: "ExtraExtraLong", year: 2018, director: "Donald Putin"))

我遇到的问题是Name变量的输出实际上与Director变量相同，我无法弄清楚原因。 名称值out的长度通常与名称值的长度相同，这意味着如果Director长于名称，则只有部分director值被分配给名称值，尽管不正确。

我的出局看起来像这样：

名称值为：ExtraLong，Director Value in：Bob Ross

成功插入行

名称 - ＆gt;鲍勃罗斯

导演 - ＆gt;鲍勃罗斯

名称价值是：鲍勃罗斯，董事价值出来是：鲍勃罗斯